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5d637d5a PB |
1 | /* |
2 | * Copyright (C) 2014 Fraunhofer ITWM | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 | |
6 | * as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | * Written by: | |
14 | * Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de> | |
15 | */ | |
16 | ||
17 | #include <linux/err.h> | |
18 | #include <linux/bug.h> | |
19 | #include <linux/completion.h> | |
20 | #include <net/ieee802154.h> | |
4c14a2fb | 21 | #include <crypto/algapi.h> |
5d637d5a PB |
22 | |
23 | #include "mac802154.h" | |
24 | #include "llsec.h" | |
25 | ||
26 | static void llsec_key_put(struct mac802154_llsec_key *key); | |
27 | static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a, | |
28 | const struct ieee802154_llsec_key_id *b); | |
29 | ||
30 | static void llsec_dev_free(struct mac802154_llsec_device *dev); | |
31 | ||
32 | void mac802154_llsec_init(struct mac802154_llsec *sec) | |
33 | { | |
34 | memset(sec, 0, sizeof(*sec)); | |
35 | ||
36 | memset(&sec->params.default_key_source, 0xFF, IEEE802154_ADDR_LEN); | |
37 | ||
38 | INIT_LIST_HEAD(&sec->table.security_levels); | |
39 | INIT_LIST_HEAD(&sec->table.devices); | |
40 | INIT_LIST_HEAD(&sec->table.keys); | |
41 | hash_init(sec->devices_short); | |
42 | hash_init(sec->devices_hw); | |
43 | rwlock_init(&sec->lock); | |
44 | } | |
45 | ||
46 | void mac802154_llsec_destroy(struct mac802154_llsec *sec) | |
47 | { | |
48 | struct ieee802154_llsec_seclevel *sl, *sn; | |
49 | struct ieee802154_llsec_device *dev, *dn; | |
50 | struct ieee802154_llsec_key_entry *key, *kn; | |
51 | ||
52 | list_for_each_entry_safe(sl, sn, &sec->table.security_levels, list) { | |
53 | struct mac802154_llsec_seclevel *msl; | |
54 | ||
55 | msl = container_of(sl, struct mac802154_llsec_seclevel, level); | |
56 | list_del(&sl->list); | |
57 | kfree(msl); | |
58 | } | |
59 | ||
60 | list_for_each_entry_safe(dev, dn, &sec->table.devices, list) { | |
61 | struct mac802154_llsec_device *mdev; | |
62 | ||
63 | mdev = container_of(dev, struct mac802154_llsec_device, dev); | |
64 | list_del(&dev->list); | |
65 | llsec_dev_free(mdev); | |
66 | } | |
67 | ||
68 | list_for_each_entry_safe(key, kn, &sec->table.keys, list) { | |
69 | struct mac802154_llsec_key *mkey; | |
70 | ||
71 | mkey = container_of(key->key, struct mac802154_llsec_key, key); | |
72 | list_del(&key->list); | |
73 | llsec_key_put(mkey); | |
74 | kfree(key); | |
75 | } | |
76 | } | |
77 | ||
78 | ||
79 | ||
80 | int mac802154_llsec_get_params(struct mac802154_llsec *sec, | |
81 | struct ieee802154_llsec_params *params) | |
82 | { | |
83 | read_lock_bh(&sec->lock); | |
84 | *params = sec->params; | |
85 | read_unlock_bh(&sec->lock); | |
86 | ||
87 | return 0; | |
88 | } | |
89 | ||
90 | int mac802154_llsec_set_params(struct mac802154_llsec *sec, | |
91 | const struct ieee802154_llsec_params *params, | |
92 | int changed) | |
93 | { | |
94 | write_lock_bh(&sec->lock); | |
95 | ||
96 | if (changed & IEEE802154_LLSEC_PARAM_ENABLED) | |
97 | sec->params.enabled = params->enabled; | |
98 | if (changed & IEEE802154_LLSEC_PARAM_FRAME_COUNTER) | |
99 | sec->params.frame_counter = params->frame_counter; | |
100 | if (changed & IEEE802154_LLSEC_PARAM_OUT_LEVEL) | |
101 | sec->params.out_level = params->out_level; | |
102 | if (changed & IEEE802154_LLSEC_PARAM_OUT_KEY) | |
103 | sec->params.out_key = params->out_key; | |
104 | if (changed & IEEE802154_LLSEC_PARAM_KEY_SOURCE) | |
105 | sec->params.default_key_source = params->default_key_source; | |
106 | if (changed & IEEE802154_LLSEC_PARAM_PAN_ID) | |
107 | sec->params.pan_id = params->pan_id; | |
108 | if (changed & IEEE802154_LLSEC_PARAM_HWADDR) | |
109 | sec->params.hwaddr = params->hwaddr; | |
110 | if (changed & IEEE802154_LLSEC_PARAM_COORD_HWADDR) | |
111 | sec->params.coord_hwaddr = params->coord_hwaddr; | |
112 | if (changed & IEEE802154_LLSEC_PARAM_COORD_SHORTADDR) | |
113 | sec->params.coord_shortaddr = params->coord_shortaddr; | |
114 | ||
115 | write_unlock_bh(&sec->lock); | |
116 | ||
117 | return 0; | |
118 | } | |
119 | ||
120 | ||
121 | ||
122 | static struct mac802154_llsec_key* | |
123 | llsec_key_alloc(const struct ieee802154_llsec_key *template) | |
124 | { | |
125 | const int authsizes[3] = { 4, 8, 16 }; | |
126 | struct mac802154_llsec_key *key; | |
127 | int i; | |
128 | ||
129 | key = kzalloc(sizeof(*key), GFP_KERNEL); | |
130 | if (!key) | |
131 | return NULL; | |
132 | ||
133 | kref_init(&key->ref); | |
134 | key->key = *template; | |
135 | ||
136 | BUILD_BUG_ON(ARRAY_SIZE(authsizes) != ARRAY_SIZE(key->tfm)); | |
137 | ||
138 | for (i = 0; i < ARRAY_SIZE(key->tfm); i++) { | |
139 | key->tfm[i] = crypto_alloc_aead("ccm(aes)", 0, | |
140 | CRYPTO_ALG_ASYNC); | |
141 | if (!key->tfm[i]) | |
142 | goto err_tfm; | |
143 | if (crypto_aead_setkey(key->tfm[i], template->key, | |
144 | IEEE802154_LLSEC_KEY_SIZE)) | |
145 | goto err_tfm; | |
146 | if (crypto_aead_setauthsize(key->tfm[i], authsizes[i])) | |
147 | goto err_tfm; | |
148 | } | |
149 | ||
150 | key->tfm0 = crypto_alloc_blkcipher("ctr(aes)", 0, CRYPTO_ALG_ASYNC); | |
151 | if (!key->tfm0) | |
152 | goto err_tfm; | |
153 | ||
154 | if (crypto_blkcipher_setkey(key->tfm0, template->key, | |
155 | IEEE802154_LLSEC_KEY_SIZE)) | |
156 | goto err_tfm0; | |
157 | ||
158 | return key; | |
159 | ||
160 | err_tfm0: | |
161 | crypto_free_blkcipher(key->tfm0); | |
162 | err_tfm: | |
163 | for (i = 0; i < ARRAY_SIZE(key->tfm); i++) | |
164 | if (key->tfm[i]) | |
165 | crypto_free_aead(key->tfm[i]); | |
166 | ||
167 | kfree(key); | |
168 | return NULL; | |
169 | } | |
170 | ||
171 | static void llsec_key_release(struct kref *ref) | |
172 | { | |
173 | struct mac802154_llsec_key *key; | |
174 | int i; | |
175 | ||
176 | key = container_of(ref, struct mac802154_llsec_key, ref); | |
177 | ||
178 | for (i = 0; i < ARRAY_SIZE(key->tfm); i++) | |
179 | crypto_free_aead(key->tfm[i]); | |
180 | ||
181 | crypto_free_blkcipher(key->tfm0); | |
182 | kfree(key); | |
183 | } | |
184 | ||
185 | static struct mac802154_llsec_key* | |
186 | llsec_key_get(struct mac802154_llsec_key *key) | |
187 | { | |
188 | kref_get(&key->ref); | |
189 | return key; | |
190 | } | |
191 | ||
192 | static void llsec_key_put(struct mac802154_llsec_key *key) | |
193 | { | |
194 | kref_put(&key->ref, llsec_key_release); | |
195 | } | |
196 | ||
197 | static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a, | |
198 | const struct ieee802154_llsec_key_id *b) | |
199 | { | |
200 | if (a->mode != b->mode) | |
201 | return false; | |
202 | ||
203 | if (a->mode == IEEE802154_SCF_KEY_IMPLICIT) | |
204 | return ieee802154_addr_equal(&a->device_addr, &b->device_addr); | |
205 | ||
206 | if (a->id != b->id) | |
207 | return false; | |
208 | ||
209 | switch (a->mode) { | |
210 | case IEEE802154_SCF_KEY_SHORT_INDEX: | |
211 | return a->short_source == b->short_source; | |
212 | case IEEE802154_SCF_KEY_HW_INDEX: | |
213 | return a->extended_source == b->extended_source; | |
214 | } | |
215 | ||
216 | return false; | |
217 | } | |
218 | ||
219 | int mac802154_llsec_key_add(struct mac802154_llsec *sec, | |
220 | const struct ieee802154_llsec_key_id *id, | |
221 | const struct ieee802154_llsec_key *key) | |
222 | { | |
223 | struct mac802154_llsec_key *mkey = NULL; | |
224 | struct ieee802154_llsec_key_entry *pos, *new; | |
225 | ||
226 | if (!(key->frame_types & (1 << IEEE802154_FC_TYPE_MAC_CMD)) && | |
227 | key->cmd_frame_ids) | |
228 | return -EINVAL; | |
229 | ||
230 | list_for_each_entry(pos, &sec->table.keys, list) { | |
231 | if (llsec_key_id_equal(&pos->id, id)) | |
232 | return -EEXIST; | |
233 | ||
234 | if (memcmp(pos->key->key, key->key, | |
235 | IEEE802154_LLSEC_KEY_SIZE)) | |
236 | continue; | |
237 | ||
238 | mkey = container_of(pos->key, struct mac802154_llsec_key, key); | |
239 | ||
240 | /* Don't allow multiple instances of the same AES key to have | |
241 | * different allowed frame types/command frame ids, as this is | |
242 | * not possible in the 802.15.4 PIB. | |
243 | */ | |
244 | if (pos->key->frame_types != key->frame_types || | |
245 | pos->key->cmd_frame_ids != key->cmd_frame_ids) | |
246 | return -EEXIST; | |
247 | ||
248 | break; | |
249 | } | |
250 | ||
251 | new = kzalloc(sizeof(*new), GFP_KERNEL); | |
252 | if (!new) | |
253 | return -ENOMEM; | |
254 | ||
255 | if (!mkey) | |
256 | mkey = llsec_key_alloc(key); | |
257 | else | |
258 | mkey = llsec_key_get(mkey); | |
259 | ||
260 | if (!mkey) | |
261 | goto fail; | |
262 | ||
263 | new->id = *id; | |
264 | new->key = &mkey->key; | |
265 | ||
266 | list_add_rcu(&new->list, &sec->table.keys); | |
267 | ||
268 | return 0; | |
269 | ||
270 | fail: | |
271 | kfree(new); | |
272 | return -ENOMEM; | |
273 | } | |
274 | ||
275 | int mac802154_llsec_key_del(struct mac802154_llsec *sec, | |
276 | const struct ieee802154_llsec_key_id *key) | |
277 | { | |
278 | struct ieee802154_llsec_key_entry *pos; | |
279 | ||
280 | list_for_each_entry(pos, &sec->table.keys, list) { | |
281 | struct mac802154_llsec_key *mkey; | |
282 | ||
283 | mkey = container_of(pos->key, struct mac802154_llsec_key, key); | |
284 | ||
285 | if (llsec_key_id_equal(&pos->id, key)) { | |
286 | llsec_key_put(mkey); | |
287 | return 0; | |
288 | } | |
289 | } | |
290 | ||
291 | return -ENOENT; | |
292 | } | |
293 | ||
294 | ||
295 | ||
296 | static bool llsec_dev_use_shortaddr(__le16 short_addr) | |
297 | { | |
298 | return short_addr != cpu_to_le16(IEEE802154_ADDR_UNDEF) && | |
299 | short_addr != cpu_to_le16(0xffff); | |
300 | } | |
301 | ||
302 | static u32 llsec_dev_hash_short(__le16 short_addr, __le16 pan_id) | |
303 | { | |
304 | return ((__force u16) short_addr) << 16 | (__force u16) pan_id; | |
305 | } | |
306 | ||
307 | static u64 llsec_dev_hash_long(__le64 hwaddr) | |
308 | { | |
309 | return (__force u64) hwaddr; | |
310 | } | |
311 | ||
312 | static struct mac802154_llsec_device* | |
313 | llsec_dev_find_short(struct mac802154_llsec *sec, __le16 short_addr, | |
314 | __le16 pan_id) | |
315 | { | |
316 | struct mac802154_llsec_device *dev; | |
317 | u32 key = llsec_dev_hash_short(short_addr, pan_id); | |
318 | ||
319 | hash_for_each_possible_rcu(sec->devices_short, dev, bucket_s, key) { | |
320 | if (dev->dev.short_addr == short_addr && | |
321 | dev->dev.pan_id == pan_id) | |
322 | return dev; | |
323 | } | |
324 | ||
325 | return NULL; | |
326 | } | |
327 | ||
328 | static struct mac802154_llsec_device* | |
329 | llsec_dev_find_long(struct mac802154_llsec *sec, __le64 hwaddr) | |
330 | { | |
331 | struct mac802154_llsec_device *dev; | |
332 | u64 key = llsec_dev_hash_long(hwaddr); | |
333 | ||
334 | hash_for_each_possible_rcu(sec->devices_hw, dev, bucket_hw, key) { | |
335 | if (dev->dev.hwaddr == hwaddr) | |
336 | return dev; | |
337 | } | |
338 | ||
339 | return NULL; | |
340 | } | |
341 | ||
342 | static void llsec_dev_free(struct mac802154_llsec_device *dev) | |
343 | { | |
344 | struct ieee802154_llsec_device_key *pos, *pn; | |
345 | struct mac802154_llsec_device_key *devkey; | |
346 | ||
347 | list_for_each_entry_safe(pos, pn, &dev->dev.keys, list) { | |
348 | devkey = container_of(pos, struct mac802154_llsec_device_key, | |
349 | devkey); | |
350 | ||
351 | list_del(&pos->list); | |
352 | kfree(devkey); | |
353 | } | |
354 | ||
355 | kfree(dev); | |
356 | } | |
357 | ||
358 | int mac802154_llsec_dev_add(struct mac802154_llsec *sec, | |
359 | const struct ieee802154_llsec_device *dev) | |
360 | { | |
361 | struct mac802154_llsec_device *entry; | |
362 | u32 skey = llsec_dev_hash_short(dev->short_addr, dev->pan_id); | |
363 | u64 hwkey = llsec_dev_hash_long(dev->hwaddr); | |
364 | ||
365 | BUILD_BUG_ON(sizeof(hwkey) != IEEE802154_ADDR_LEN); | |
366 | ||
367 | if ((llsec_dev_use_shortaddr(dev->short_addr) && | |
368 | llsec_dev_find_short(sec, dev->short_addr, dev->pan_id)) || | |
369 | llsec_dev_find_long(sec, dev->hwaddr)) | |
370 | return -EEXIST; | |
371 | ||
372 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
373 | if (!entry) | |
374 | return -ENOMEM; | |
375 | ||
376 | entry->dev = *dev; | |
377 | spin_lock_init(&entry->lock); | |
378 | INIT_LIST_HEAD(&entry->dev.keys); | |
379 | ||
380 | if (llsec_dev_use_shortaddr(dev->short_addr)) | |
381 | hash_add_rcu(sec->devices_short, &entry->bucket_s, skey); | |
382 | else | |
383 | INIT_HLIST_NODE(&entry->bucket_s); | |
384 | ||
385 | hash_add_rcu(sec->devices_hw, &entry->bucket_hw, hwkey); | |
386 | list_add_tail_rcu(&entry->dev.list, &sec->table.devices); | |
387 | ||
388 | return 0; | |
389 | } | |
390 | ||
391 | static void llsec_dev_free_rcu(struct rcu_head *rcu) | |
392 | { | |
393 | llsec_dev_free(container_of(rcu, struct mac802154_llsec_device, rcu)); | |
394 | } | |
395 | ||
396 | int mac802154_llsec_dev_del(struct mac802154_llsec *sec, __le64 device_addr) | |
397 | { | |
398 | struct mac802154_llsec_device *pos; | |
399 | ||
400 | pos = llsec_dev_find_long(sec, device_addr); | |
401 | if (!pos) | |
402 | return -ENOENT; | |
403 | ||
404 | hash_del_rcu(&pos->bucket_s); | |
405 | hash_del_rcu(&pos->bucket_hw); | |
406 | call_rcu(&pos->rcu, llsec_dev_free_rcu); | |
407 | ||
408 | return 0; | |
409 | } | |
410 | ||
411 | ||
412 | ||
413 | static struct mac802154_llsec_device_key* | |
414 | llsec_devkey_find(struct mac802154_llsec_device *dev, | |
415 | const struct ieee802154_llsec_key_id *key) | |
416 | { | |
417 | struct ieee802154_llsec_device_key *devkey; | |
418 | ||
419 | list_for_each_entry_rcu(devkey, &dev->dev.keys, list) { | |
420 | if (!llsec_key_id_equal(key, &devkey->key_id)) | |
421 | continue; | |
422 | ||
423 | return container_of(devkey, struct mac802154_llsec_device_key, | |
424 | devkey); | |
425 | } | |
426 | ||
427 | return NULL; | |
428 | } | |
429 | ||
430 | int mac802154_llsec_devkey_add(struct mac802154_llsec *sec, | |
431 | __le64 dev_addr, | |
432 | const struct ieee802154_llsec_device_key *key) | |
433 | { | |
434 | struct mac802154_llsec_device *dev; | |
435 | struct mac802154_llsec_device_key *devkey; | |
436 | ||
437 | dev = llsec_dev_find_long(sec, dev_addr); | |
438 | ||
439 | if (!dev) | |
440 | return -ENOENT; | |
441 | ||
442 | if (llsec_devkey_find(dev, &key->key_id)) | |
443 | return -EEXIST; | |
444 | ||
445 | devkey = kmalloc(sizeof(*devkey), GFP_KERNEL); | |
446 | if (!devkey) | |
447 | return -ENOMEM; | |
448 | ||
449 | devkey->devkey = *key; | |
450 | list_add_tail_rcu(&devkey->devkey.list, &dev->dev.keys); | |
451 | return 0; | |
452 | } | |
453 | ||
454 | int mac802154_llsec_devkey_del(struct mac802154_llsec *sec, | |
455 | __le64 dev_addr, | |
456 | const struct ieee802154_llsec_device_key *key) | |
457 | { | |
458 | struct mac802154_llsec_device *dev; | |
459 | struct mac802154_llsec_device_key *devkey; | |
460 | ||
461 | dev = llsec_dev_find_long(sec, dev_addr); | |
462 | ||
463 | if (!dev) | |
464 | return -ENOENT; | |
465 | ||
466 | devkey = llsec_devkey_find(dev, &key->key_id); | |
467 | if (!devkey) | |
468 | return -ENOENT; | |
469 | ||
470 | list_del_rcu(&devkey->devkey.list); | |
471 | kfree_rcu(devkey, rcu); | |
472 | return 0; | |
473 | } | |
474 | ||
475 | ||
476 | ||
477 | static struct mac802154_llsec_seclevel* | |
478 | llsec_find_seclevel(const struct mac802154_llsec *sec, | |
479 | const struct ieee802154_llsec_seclevel *sl) | |
480 | { | |
481 | struct ieee802154_llsec_seclevel *pos; | |
482 | ||
483 | list_for_each_entry(pos, &sec->table.security_levels, list) { | |
484 | if (pos->frame_type != sl->frame_type || | |
485 | (pos->frame_type == IEEE802154_FC_TYPE_MAC_CMD && | |
486 | pos->cmd_frame_id != sl->cmd_frame_id) || | |
487 | pos->device_override != sl->device_override || | |
488 | pos->sec_levels != sl->sec_levels) | |
489 | continue; | |
490 | ||
491 | return container_of(pos, struct mac802154_llsec_seclevel, | |
492 | level); | |
493 | } | |
494 | ||
495 | return NULL; | |
496 | } | |
497 | ||
498 | int mac802154_llsec_seclevel_add(struct mac802154_llsec *sec, | |
499 | const struct ieee802154_llsec_seclevel *sl) | |
500 | { | |
501 | struct mac802154_llsec_seclevel *entry; | |
502 | ||
503 | if (llsec_find_seclevel(sec, sl)) | |
504 | return -EEXIST; | |
505 | ||
506 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
507 | if (!entry) | |
508 | return -ENOMEM; | |
509 | ||
510 | entry->level = *sl; | |
511 | ||
512 | list_add_tail_rcu(&entry->level.list, &sec->table.security_levels); | |
513 | ||
514 | return 0; | |
515 | } | |
516 | ||
517 | int mac802154_llsec_seclevel_del(struct mac802154_llsec *sec, | |
518 | const struct ieee802154_llsec_seclevel *sl) | |
519 | { | |
520 | struct mac802154_llsec_seclevel *pos; | |
521 | ||
522 | pos = llsec_find_seclevel(sec, sl); | |
523 | if (!pos) | |
524 | return -ENOENT; | |
525 | ||
526 | list_del_rcu(&pos->level.list); | |
527 | kfree_rcu(pos, rcu); | |
528 | ||
529 | return 0; | |
530 | } | |
03556e4d PB |
531 | |
532 | ||
533 | ||
534 | static int llsec_recover_addr(struct mac802154_llsec *sec, | |
535 | struct ieee802154_addr *addr) | |
536 | { | |
537 | __le16 caddr = sec->params.coord_shortaddr; | |
538 | addr->pan_id = sec->params.pan_id; | |
539 | ||
540 | if (caddr == cpu_to_le16(IEEE802154_ADDR_BROADCAST)) { | |
541 | return -EINVAL; | |
542 | } else if (caddr == cpu_to_le16(IEEE802154_ADDR_UNDEF)) { | |
543 | addr->extended_addr = sec->params.coord_hwaddr; | |
544 | addr->mode = IEEE802154_ADDR_LONG; | |
545 | } else { | |
546 | addr->short_addr = sec->params.coord_shortaddr; | |
547 | addr->mode = IEEE802154_ADDR_SHORT; | |
548 | } | |
549 | ||
550 | return 0; | |
551 | } | |
552 | ||
553 | static struct mac802154_llsec_key* | |
554 | llsec_lookup_key(struct mac802154_llsec *sec, | |
555 | const struct ieee802154_hdr *hdr, | |
556 | const struct ieee802154_addr *addr, | |
557 | struct ieee802154_llsec_key_id *key_id) | |
558 | { | |
559 | struct ieee802154_addr devaddr = *addr; | |
560 | u8 key_id_mode = hdr->sec.key_id_mode; | |
561 | struct ieee802154_llsec_key_entry *key_entry; | |
562 | struct mac802154_llsec_key *key; | |
563 | ||
564 | if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT && | |
565 | devaddr.mode == IEEE802154_ADDR_NONE) { | |
566 | if (hdr->fc.type == IEEE802154_FC_TYPE_BEACON) { | |
567 | devaddr.extended_addr = sec->params.coord_hwaddr; | |
568 | devaddr.mode = IEEE802154_ADDR_LONG; | |
569 | } else if (llsec_recover_addr(sec, &devaddr) < 0) { | |
570 | return NULL; | |
571 | } | |
572 | } | |
573 | ||
574 | list_for_each_entry_rcu(key_entry, &sec->table.keys, list) { | |
575 | const struct ieee802154_llsec_key_id *id = &key_entry->id; | |
576 | ||
577 | if (!(key_entry->key->frame_types & BIT(hdr->fc.type))) | |
578 | continue; | |
579 | ||
580 | if (id->mode != key_id_mode) | |
581 | continue; | |
582 | ||
583 | if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT) { | |
584 | if (ieee802154_addr_equal(&devaddr, &id->device_addr)) | |
585 | goto found; | |
586 | } else { | |
587 | if (id->id != hdr->sec.key_id) | |
588 | continue; | |
589 | ||
590 | if ((key_id_mode == IEEE802154_SCF_KEY_INDEX) || | |
591 | (key_id_mode == IEEE802154_SCF_KEY_SHORT_INDEX && | |
592 | id->short_source == hdr->sec.short_src) || | |
593 | (key_id_mode == IEEE802154_SCF_KEY_HW_INDEX && | |
594 | id->extended_source == hdr->sec.extended_src)) | |
595 | goto found; | |
596 | } | |
597 | } | |
598 | ||
599 | return NULL; | |
600 | ||
601 | found: | |
602 | key = container_of(key_entry->key, struct mac802154_llsec_key, key); | |
603 | if (key_id) | |
604 | *key_id = key_entry->id; | |
605 | return llsec_key_get(key); | |
606 | } | |
607 | ||
608 | ||
609 | static void llsec_geniv(u8 iv[16], __le64 addr, | |
610 | const struct ieee802154_sechdr *sec) | |
611 | { | |
612 | __be64 addr_bytes = (__force __be64) swab64((__force u64) addr); | |
613 | __be32 frame_counter = (__force __be32) swab32((__force u32) sec->frame_counter); | |
614 | ||
615 | iv[0] = 1; /* L' = L - 1 = 1 */ | |
616 | memcpy(iv + 1, &addr_bytes, sizeof(addr_bytes)); | |
617 | memcpy(iv + 9, &frame_counter, sizeof(frame_counter)); | |
618 | iv[13] = sec->level; | |
619 | iv[14] = 0; | |
620 | iv[15] = 1; | |
621 | } | |
622 | ||
623 | static int | |
624 | llsec_do_encrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec, | |
625 | const struct ieee802154_hdr *hdr, | |
626 | struct mac802154_llsec_key *key) | |
627 | { | |
628 | u8 iv[16]; | |
629 | struct scatterlist src; | |
630 | struct blkcipher_desc req = { | |
631 | .tfm = key->tfm0, | |
632 | .info = iv, | |
633 | .flags = 0, | |
634 | }; | |
635 | ||
636 | llsec_geniv(iv, sec->params.hwaddr, &hdr->sec); | |
637 | sg_init_one(&src, skb->data, skb->len); | |
638 | return crypto_blkcipher_encrypt_iv(&req, &src, &src, skb->len); | |
639 | } | |
640 | ||
641 | static struct crypto_aead* | |
642 | llsec_tfm_by_len(struct mac802154_llsec_key *key, int authlen) | |
643 | { | |
644 | int i; | |
645 | ||
646 | for (i = 0; i < ARRAY_SIZE(key->tfm); i++) | |
647 | if (crypto_aead_authsize(key->tfm[i]) == authlen) | |
648 | return key->tfm[i]; | |
649 | ||
650 | BUG(); | |
651 | } | |
652 | ||
653 | static int | |
654 | llsec_do_encrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec, | |
655 | const struct ieee802154_hdr *hdr, | |
656 | struct mac802154_llsec_key *key) | |
657 | { | |
658 | u8 iv[16]; | |
659 | unsigned char *data; | |
660 | int authlen, assoclen, datalen, rc; | |
661 | struct scatterlist src, assoc[2], dst[2]; | |
662 | struct aead_request *req; | |
663 | ||
664 | authlen = ieee802154_sechdr_authtag_len(&hdr->sec); | |
665 | llsec_geniv(iv, sec->params.hwaddr, &hdr->sec); | |
666 | ||
667 | req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC); | |
668 | if (!req) | |
669 | return -ENOMEM; | |
670 | ||
671 | sg_init_table(assoc, 2); | |
672 | sg_set_buf(&assoc[0], skb_mac_header(skb), skb->mac_len); | |
673 | assoclen = skb->mac_len; | |
674 | ||
675 | data = skb_mac_header(skb) + skb->mac_len; | |
676 | datalen = skb_tail_pointer(skb) - data; | |
677 | ||
678 | if (hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC) { | |
679 | sg_set_buf(&assoc[1], data, 0); | |
680 | } else { | |
681 | sg_set_buf(&assoc[1], data, datalen); | |
682 | assoclen += datalen; | |
683 | datalen = 0; | |
684 | } | |
685 | ||
686 | sg_init_one(&src, data, datalen); | |
687 | ||
688 | sg_init_table(dst, 2); | |
689 | sg_set_buf(&dst[0], data, datalen); | |
690 | sg_set_buf(&dst[1], skb_put(skb, authlen), authlen); | |
691 | ||
692 | aead_request_set_callback(req, 0, NULL, NULL); | |
693 | aead_request_set_assoc(req, assoc, assoclen); | |
694 | aead_request_set_crypt(req, &src, dst, datalen, iv); | |
695 | ||
696 | rc = crypto_aead_encrypt(req); | |
697 | ||
698 | kfree(req); | |
699 | ||
700 | return rc; | |
701 | } | |
702 | ||
703 | static int llsec_do_encrypt(struct sk_buff *skb, | |
704 | const struct mac802154_llsec *sec, | |
705 | const struct ieee802154_hdr *hdr, | |
706 | struct mac802154_llsec_key *key) | |
707 | { | |
708 | if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC) | |
709 | return llsec_do_encrypt_unauth(skb, sec, hdr, key); | |
710 | else | |
711 | return llsec_do_encrypt_auth(skb, sec, hdr, key); | |
712 | } | |
713 | ||
714 | int mac802154_llsec_encrypt(struct mac802154_llsec *sec, struct sk_buff *skb) | |
715 | { | |
716 | struct ieee802154_hdr hdr; | |
717 | int rc, authlen, hlen; | |
718 | struct mac802154_llsec_key *key; | |
719 | u32 frame_ctr; | |
720 | ||
721 | hlen = ieee802154_hdr_pull(skb, &hdr); | |
722 | ||
723 | if (hlen < 0 || hdr.fc.type != IEEE802154_FC_TYPE_DATA) | |
724 | return -EINVAL; | |
725 | ||
726 | if (!hdr.fc.security_enabled || hdr.sec.level == 0) { | |
727 | skb_push(skb, hlen); | |
728 | return 0; | |
729 | } | |
730 | ||
731 | authlen = ieee802154_sechdr_authtag_len(&hdr.sec); | |
732 | ||
733 | if (skb->len + hlen + authlen + IEEE802154_MFR_SIZE > IEEE802154_MTU) | |
734 | return -EMSGSIZE; | |
735 | ||
736 | rcu_read_lock(); | |
737 | ||
738 | read_lock_bh(&sec->lock); | |
739 | ||
740 | if (!sec->params.enabled) { | |
741 | rc = -EINVAL; | |
742 | goto fail_read; | |
743 | } | |
744 | ||
745 | key = llsec_lookup_key(sec, &hdr, &hdr.dest, NULL); | |
746 | if (!key) { | |
747 | rc = -ENOKEY; | |
748 | goto fail_read; | |
749 | } | |
750 | ||
751 | read_unlock_bh(&sec->lock); | |
752 | ||
753 | write_lock_bh(&sec->lock); | |
754 | ||
755 | frame_ctr = be32_to_cpu(sec->params.frame_counter); | |
756 | hdr.sec.frame_counter = cpu_to_le32(frame_ctr); | |
757 | if (frame_ctr == 0xFFFFFFFF) { | |
758 | write_unlock_bh(&sec->lock); | |
759 | llsec_key_put(key); | |
760 | rc = -EOVERFLOW; | |
761 | goto fail; | |
762 | } | |
763 | ||
764 | sec->params.frame_counter = cpu_to_be32(frame_ctr + 1); | |
765 | ||
766 | write_unlock_bh(&sec->lock); | |
767 | ||
768 | rcu_read_unlock(); | |
769 | ||
770 | skb->mac_len = ieee802154_hdr_push(skb, &hdr); | |
771 | skb_reset_mac_header(skb); | |
772 | ||
773 | rc = llsec_do_encrypt(skb, sec, &hdr, key); | |
774 | llsec_key_put(key); | |
775 | ||
776 | return rc < 0 ? rc : 0; | |
777 | ||
778 | fail_read: | |
779 | read_unlock(&sec->lock); | |
780 | fail: | |
781 | rcu_read_unlock(); | |
782 | return rc; | |
783 | } | |
4c14a2fb PB |
784 | |
785 | ||
786 | ||
787 | static struct mac802154_llsec_device* | |
788 | llsec_lookup_dev(struct mac802154_llsec *sec, | |
789 | const struct ieee802154_addr *addr) | |
790 | { | |
791 | struct ieee802154_addr devaddr = *addr; | |
792 | struct mac802154_llsec_device *dev = NULL; | |
793 | ||
794 | if (devaddr.mode == IEEE802154_ADDR_NONE && | |
795 | llsec_recover_addr(sec, &devaddr) < 0) | |
796 | return NULL; | |
797 | ||
798 | if (devaddr.mode == IEEE802154_ADDR_SHORT) { | |
799 | u32 key = llsec_dev_hash_short(devaddr.short_addr, | |
800 | devaddr.pan_id); | |
801 | ||
802 | hash_for_each_possible_rcu(sec->devices_short, dev, | |
803 | bucket_s, key) { | |
804 | if (dev->dev.pan_id == devaddr.pan_id && | |
805 | dev->dev.short_addr == devaddr.short_addr) | |
806 | return dev; | |
807 | } | |
808 | } else { | |
809 | u64 key = llsec_dev_hash_long(devaddr.extended_addr); | |
810 | ||
811 | hash_for_each_possible_rcu(sec->devices_hw, dev, | |
812 | bucket_hw, key) { | |
813 | if (dev->dev.hwaddr == devaddr.extended_addr) | |
814 | return dev; | |
815 | } | |
816 | } | |
817 | ||
818 | return NULL; | |
819 | } | |
820 | ||
821 | static int | |
822 | llsec_lookup_seclevel(const struct mac802154_llsec *sec, | |
823 | u8 frame_type, u8 cmd_frame_id, | |
824 | struct ieee802154_llsec_seclevel *rlevel) | |
825 | { | |
826 | struct ieee802154_llsec_seclevel *level; | |
827 | ||
828 | list_for_each_entry_rcu(level, &sec->table.security_levels, list) { | |
829 | if (level->frame_type == frame_type && | |
830 | (frame_type != IEEE802154_FC_TYPE_MAC_CMD || | |
831 | level->cmd_frame_id == cmd_frame_id)) { | |
832 | *rlevel = *level; | |
833 | return 0; | |
834 | } | |
835 | } | |
836 | ||
837 | return -EINVAL; | |
838 | } | |
839 | ||
840 | static int | |
841 | llsec_do_decrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec, | |
842 | const struct ieee802154_hdr *hdr, | |
843 | struct mac802154_llsec_key *key, __le64 dev_addr) | |
844 | { | |
845 | u8 iv[16]; | |
846 | unsigned char *data; | |
847 | int datalen; | |
848 | struct scatterlist src; | |
849 | struct blkcipher_desc req = { | |
850 | .tfm = key->tfm0, | |
851 | .info = iv, | |
852 | .flags = 0, | |
853 | }; | |
854 | ||
855 | llsec_geniv(iv, dev_addr, &hdr->sec); | |
856 | data = skb_mac_header(skb) + skb->mac_len; | |
857 | datalen = skb_tail_pointer(skb) - data; | |
858 | ||
859 | sg_init_one(&src, data, datalen); | |
860 | ||
861 | return crypto_blkcipher_decrypt_iv(&req, &src, &src, datalen); | |
862 | } | |
863 | ||
864 | static int | |
865 | llsec_do_decrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec, | |
866 | const struct ieee802154_hdr *hdr, | |
867 | struct mac802154_llsec_key *key, __le64 dev_addr) | |
868 | { | |
869 | u8 iv[16]; | |
870 | unsigned char *data; | |
871 | int authlen, datalen, assoclen, rc; | |
872 | struct scatterlist src, assoc[2]; | |
873 | struct aead_request *req; | |
874 | ||
875 | authlen = ieee802154_sechdr_authtag_len(&hdr->sec); | |
876 | llsec_geniv(iv, dev_addr, &hdr->sec); | |
877 | ||
878 | req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC); | |
879 | if (!req) | |
880 | return -ENOMEM; | |
881 | ||
882 | sg_init_table(assoc, 2); | |
883 | sg_set_buf(&assoc[0], skb_mac_header(skb), skb->mac_len); | |
884 | assoclen = skb->mac_len; | |
885 | ||
886 | data = skb_mac_header(skb) + skb->mac_len; | |
887 | datalen = skb_tail_pointer(skb) - data; | |
888 | ||
889 | if (hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC) { | |
890 | sg_set_buf(&assoc[1], data, 0); | |
891 | } else { | |
892 | sg_set_buf(&assoc[1], data, datalen - authlen); | |
893 | assoclen += datalen - authlen; | |
894 | data += datalen - authlen; | |
895 | datalen = authlen; | |
896 | } | |
897 | ||
898 | sg_init_one(&src, data, datalen); | |
899 | ||
900 | aead_request_set_callback(req, 0, NULL, NULL); | |
901 | aead_request_set_assoc(req, assoc, assoclen); | |
902 | aead_request_set_crypt(req, &src, &src, datalen, iv); | |
903 | ||
904 | rc = crypto_aead_decrypt(req); | |
905 | ||
906 | kfree(req); | |
907 | skb_trim(skb, skb->len - authlen); | |
908 | ||
909 | return rc; | |
910 | } | |
911 | ||
912 | static int | |
913 | llsec_do_decrypt(struct sk_buff *skb, const struct mac802154_llsec *sec, | |
914 | const struct ieee802154_hdr *hdr, | |
915 | struct mac802154_llsec_key *key, __le64 dev_addr) | |
916 | { | |
917 | if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC) | |
918 | return llsec_do_decrypt_unauth(skb, sec, hdr, key, dev_addr); | |
919 | else | |
920 | return llsec_do_decrypt_auth(skb, sec, hdr, key, dev_addr); | |
921 | } | |
922 | ||
923 | static int | |
924 | llsec_update_devkey_info(struct mac802154_llsec_device *dev, | |
925 | const struct ieee802154_llsec_key_id *in_key, | |
926 | u32 frame_counter) | |
927 | { | |
928 | struct mac802154_llsec_device_key *devkey = NULL; | |
929 | ||
930 | if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RESTRICT) { | |
931 | devkey = llsec_devkey_find(dev, in_key); | |
932 | if (!devkey) | |
933 | return -ENOENT; | |
934 | } | |
935 | ||
936 | spin_lock_bh(&dev->lock); | |
937 | ||
938 | if ((!devkey && frame_counter < dev->dev.frame_counter) || | |
939 | (devkey && frame_counter < devkey->devkey.frame_counter)) { | |
940 | spin_unlock_bh(&dev->lock); | |
941 | return -EINVAL; | |
942 | } | |
943 | ||
944 | if (devkey) | |
945 | devkey->devkey.frame_counter = frame_counter + 1; | |
946 | else | |
947 | dev->dev.frame_counter = frame_counter + 1; | |
948 | ||
949 | spin_unlock_bh(&dev->lock); | |
950 | ||
951 | return 0; | |
952 | } | |
953 | ||
954 | int mac802154_llsec_decrypt(struct mac802154_llsec *sec, struct sk_buff *skb) | |
955 | { | |
956 | struct ieee802154_hdr hdr; | |
957 | struct mac802154_llsec_key *key; | |
958 | struct ieee802154_llsec_key_id key_id; | |
959 | struct mac802154_llsec_device *dev; | |
960 | struct ieee802154_llsec_seclevel seclevel; | |
961 | int err; | |
962 | __le64 dev_addr; | |
963 | u32 frame_ctr; | |
964 | ||
965 | if (ieee802154_hdr_peek(skb, &hdr) < 0) | |
966 | return -EINVAL; | |
967 | if (!hdr.fc.security_enabled) | |
968 | return 0; | |
969 | if (hdr.fc.version == 0) | |
970 | return -EINVAL; | |
971 | ||
972 | read_lock_bh(&sec->lock); | |
973 | if (!sec->params.enabled) { | |
974 | read_unlock_bh(&sec->lock); | |
975 | return -EINVAL; | |
976 | } | |
977 | read_unlock_bh(&sec->lock); | |
978 | ||
979 | rcu_read_lock(); | |
980 | ||
981 | key = llsec_lookup_key(sec, &hdr, &hdr.source, &key_id); | |
982 | if (!key) { | |
983 | err = -ENOKEY; | |
984 | goto fail; | |
985 | } | |
986 | ||
987 | dev = llsec_lookup_dev(sec, &hdr.source); | |
988 | if (!dev) { | |
989 | err = -EINVAL; | |
990 | goto fail_dev; | |
991 | } | |
992 | ||
993 | if (llsec_lookup_seclevel(sec, hdr.fc.type, 0, &seclevel) < 0) { | |
994 | err = -EINVAL; | |
995 | goto fail_dev; | |
996 | } | |
997 | ||
998 | if (!(seclevel.sec_levels & BIT(hdr.sec.level)) && | |
999 | (hdr.sec.level == 0 && seclevel.device_override && | |
1000 | !dev->dev.seclevel_exempt)) { | |
1001 | err = -EINVAL; | |
1002 | goto fail_dev; | |
1003 | } | |
1004 | ||
1005 | frame_ctr = le32_to_cpu(hdr.sec.frame_counter); | |
1006 | ||
1007 | if (frame_ctr == 0xffffffff) { | |
1008 | err = -EOVERFLOW; | |
1009 | goto fail_dev; | |
1010 | } | |
1011 | ||
1012 | err = llsec_update_devkey_info(dev, &key_id, frame_ctr); | |
1013 | if (err) | |
1014 | goto fail_dev; | |
1015 | ||
1016 | dev_addr = dev->dev.hwaddr; | |
1017 | ||
1018 | rcu_read_unlock(); | |
1019 | ||
1020 | err = llsec_do_decrypt(skb, sec, &hdr, key, dev_addr); | |
1021 | llsec_key_put(key); | |
1022 | return err; | |
1023 | ||
1024 | fail_dev: | |
1025 | llsec_key_put(key); | |
1026 | fail: | |
1027 | rcu_read_unlock(); | |
1028 | return err; | |
1029 | } |